When evaluating the hydraulic properties of water for fire protection system, what is the measurement...

The measurement of a fluid’s resistance to flow is calledviscosity.Viscosity is the property of a fluid that describes how easily it can deform or move when subjected to a shear stress, such as the force exerted by a pipe wall or a pump1. A fluid with high viscosity, such as honey, resists flow and requires more pressure to overcome the friction between its layers.A fluid with low viscosity, such as water, flows easily and has less frictional resistance2.Viscosity affects the hydraulic properties of water for fire protection systems, such as the flow rate, pressure loss, and pump power3. Viscosity is usually expressed in units of pascal-second (Pa s) or centipoise (cP) for liquids, and is dependent on the temperature and composition of the fluid.References:

Viscosity | Definition, Facts, Formula, Units, & Examples

Viscosity – The Physics Hypertextbook

Fire Pump Types | NFPA

[12.4: Viscosity and Laminar Flow; Poiseuille’s Law]